Well fluid sampler



July 31, 1962 B. A. PETERS ETAL 3,047,072

WELL FLUID SAMPLER Filed Feb, 15, 1961 F|G.2A. In F|G.2B.

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AT TORNEL United States 3,047,072 Patented uiy 31, 1962 3,047,072 WELLFLUD SAMPLER Belden A. Peters and Eivis Rich, Houston, Tex., assiguors,by mesne assignments, to .iersey Production Research Company, rlulsa,Sida., a corporation of Delaware Filed Feb. 15, 1961, Ser. No. 89,491 3Ciaims. (Cl. 166-164) This Iinvention relates to apparatus forlobtaining uid samples, and more particularly to apparatus for obtaininguid samples under reservoir conditions in well hores.

For a number of reasons it is important to obtain samples of iiuids atvarious levels in well bores, the most important reason being todetermine conditions and methods of production that will recover themaximum quantity of hydrocarbonaceous uids from hydrocarboncontainingreservoirs. inasmuch Ias hydrocarbon oil and gas produced at the surfaceof the ground has qui-te different physical characteristics at normal`atmospheric temperature and pressure than the same liuids have in -thereservoir at superatmospheric temperature and pressure, it is necessaryto use special apparatus to obtain fluid samples which are trulyrepresentative of reservoir conditions.

In connection with the present invention, there is provided an elongatedhousing adapted to be lowered into a well ibore which contains a samplechamber. A passageway is provided from the exterior of the housing tothe sample chamber, along with means including an elongated -rod memberfor controlling fluid access into the chamber. The rod member is biasedby a' spring to an operative position thereof whereat the chamber isopened to fluid entry thereinto. Means including a scar is positicned inthe housing to hold the rod away from said operative position thereof sothat luid entry into the chamber is prevented. For the purpose ofcontrolling movement of the Sear, there is provided a timing motor, acam follower on the scar, and a rotatable cam means including a camsurface and a lost motion coupling to the motor. The cam is rotatively-driven by the motor, and the cam follower is positioned to follow thecam surface. The cam surface has a substantially constant radius portionand a valley portion such that the cam follower holds the Sear in therod-holding position thereof while following the constant radius portionof the cam surface, and releases the sear when following the valleyportion of the cam surface, whereby the rod is released by the Sear toopen the sample chamber.

Objects and features of the invention not apparent from the abovediscussion will become evident upon consideration of the followingdescription when taken in connection with the accompanying drawings,wherein:

FIG. 1 is an elevational View of the invention in position in a wellbore;

FIGS. 2A and 2B are cross-sectional, elevational views of the inventionillustrating `details of construction thereof;

FIG. 3 is a cross-sectional view taken along section 3 3 of FlG. 2; and

FIG. 4 is a cross-sectional view taken along section 4 4 of FIG. 2.

With reference now to FIG. 1, there is shown a well bore 1 filled withwell uid 3 to 'be sampled. An elongated housing 5 is shown suspended inwell bore 1 at the end of a wire line 7. As shown more perspicuously inFIGS. 2A and ZB, the housing includes Ia timing motor section 9, vamiddle section i1, and a sample chamber section 13.

Positioned within the timing motor section 9 is a mechanically orelectrically energized clock timing motor having an output shaft 17. Thetiming motor 15 is supported in the timing motor section 9' by suitableshock absorbing mounting devices 19. Ball bearings 21 sup- 2 port theoutput shaft within the housing so Ias to permit free rotation of theshaft. If an electric timing motor is used, it may be energized eitherby batteries (not shown) in the housing, or by a power source at thesurface through an insulated conductor in cable 7 in the usual maner forlogging instruments.

The sample chamber within housing section 13 has a single openingthereinto provided by a passageway from the exterior of the housing intothe sample chamber. The passageway includes one or more ports 25 betweenthe exterior of the housing into a chamber 27, a passageway 29 from thechamber 27, and a check valve 31 from passageway 29 into the samplechamber. The check valve v31 includes a conventional ball 35 and coilspring 33 arrangement adapted to oppose iiuid entry into the chamberuntil a predetermined pressure exerted thereon from the exterior `oflthe chamber relative to the pressure within the chamber. The checkvalve positively prevents tiuid egress from the chamber. A frangibledisk 37 is provided for the purpose iof sealing the chamber against uidentry thereinto until the apparatus is at a desired depth in a well.

-Positioned immediately above the frangible `disk is a spear-like rodmember 39 having a spear point 41 adapted to puncture or shatterfrangible disk 37 when rod 39 is driven at disk 37 under Ithe impetus of'coil spring 43. Coil spring 43V is positioned between a threaded guidenut 45 and an annular ange 47 lon lthe rod 39. Downward movement of therod is stopped when the auge 47 engages the lower end 49 of compartment51. Ports 53 provide fluid communiction between compartment 51 andchamber Z7 so as to permit free movement of the rod 39. rlfhe upper endof rod 39 includes an annular tiange or cap 55. The hook portion 57 of asear 59 is adapted to engage the under portion of the flange 55 so as tohold `the rod 39 away from the frangible disk 37 against the force ofspring 43. The sear 59 is pivoted on rod 61 on nipple member 63. Housedwithin `a recess 65 in nipple 63 is a coil spring 67 engaging `sear 59so as to bias the scar 59 away from the 'position at which the hookportion 57 `engages the rod flan-ge 55. At the opposite end of the sear59 is yaiiixed a cam follower 69, which may be a roller member.

Connection between the timing motor youtput: shaft 17 and cam follower69 is provided by shaft 79, pin 77, and cam 71. The square end 78 ofshaft 79 is connected to output shaft 17 by a coupling sleeve 80. Shaft79 is supported by ball `bearing assembly .21 and by sleeve hearing 70.An annular seal 83 held in position `around shaft 7 9 by packing nut 82prevents `fluid entry into timing motor section 9 from housing section11.

The cam 71 and shaft 79 may be considered as a cam assembly having alost motion coupling. The details of construction of the cam are bestseen in FIGS. 3 and 4. The coupling section 73 of the cam 71 includes acutout section 75 adapted to receive the driving pin 77 connected toshaft 79. The cutout section extends over an .arc of between 45 and 90.

The cam surface 72 of cam 71 includes a substantially constant radiusportion which preferably extends over at least 270 of the surface, and avalley portion 74 which preferably extends over somewhat less than ofthe surface. The cam follower 69 engages the cam surface 72 so as tohold the sear in the position shown in FIG.

2A whereat the rod 39 is held away from disk 37 while the cam follower69 is following the constant radius p0rtion of cam surface 72. When thecam follower 69 rolls into valley 74, the cam will almost instantlyrotate through the angle of movement defined by cutout 75 to releasesear 59 for pivotal motion under the impetus of spring 67.

The operation of the above-described apparatus is as follows. The timingmotor is wound or energized ,and the housing sections 9 and 13 areconnected together. Coupling section t? with slip over square shaft end78. Frangible disk 37 is inserted in housing section 13 and locked inplace with disk retaining screw 2S. To cock the apparatus, spear rod 39is pushed upwardly, as viewed, and motor 15 is rotated until camfollower 69 rides at a esircd'position oncam surface 72. Housing section13 is then connected to section 11.

The apparatus is lowered into the Well until it is at a desired depth.Timing motor will rotate shaft 79' and cam 71 throughrthe lost motioncoupling until cam follower 69 enters cam valley 74. The cam willinstantly rotate through the angle allowed by the lost motion couplingand sear 59 will pivot to release rod 39 so that spear'end 41 puncturesdisk 37. inasmuch as the fluid pressure at well depths is substantiallygreater than the atmospheric pressure within chamber 23, check valve 31will open to permit uid flow into chamber 23. When the differentialpressure between the well bore l and the chamber 23 is less than thepressure exerted by spring 33 on` ball 35, the check valve 31. willclose. The apparatus can then b e retracted from the well bore, with thefluid in chamber 23 under substantially reservoir conditions.

The present invention is particularly .advantageous in that a relativelytremendous amount of energy for actuating the well sampler is easilycontrolled by a relatively weak clockv timing motor. Clock mechanismsusedin subsurface instruments develop torques that are seldom .above 16to 18 inch ounces. The clock power is transmitted by the cam 7l and camfollower 69, Vwhich are substantially friction free, to the sear torelease the sear frornits cocked position. The cam and cam follower holdthe sear in position in a manner which makes it impossible toprematurely trip by shock. The snap action release of the. scar releasesthe scar almost instantly so that a relatively tremendous amount ofpower is available to puncture disk 37.

The invention is not necessarily to be restricted to the specificstructural details or .arrangement of parts `herein set forth, asvarious modifications thereof may be effected without departing from thespirit and scope of this invention.

What is claimed is:

1. A well sampler comprising:

a housing:

a timing motor in said housing:

a sample chamber in said housing;

means controlling duid access to said sample chamber including apassageway between said chamber and the exterior of said housing, aclosure in said passageway, an elongated rod, and spring means connectedto said rod for dirving said rod to an operative position of said rod toopen said closure and permit uid entry into said chamber;

a sear positioned in said housing to hold said rod away from saidoperative position thereof; spring'means supported in said housing andconnected to said sear for urging said sear away from the rodholdingposition thereof;

a rotatable cam assembly connected to said timing motor, including a camhaving a cam surface, and

a lost motion coupling for coupling said cam to said motor, said camsurface having a substantially constant radius portion and a valleyportion; and

' a cam follower on said sear in following relationship with said ca msurface to hold said sear inthe rodholding position thereof whilefollowing the constant radius portion of said cam, and to release saidsear from the rod-holding position thereof while following the valleyportion of said cam whereby said sear releases said rod ,to open saidsample chamber.

2. A well sampler comprising:

a housing;

a timing motor in said housing;

a sample chamber in said housing;

means controlling uid access to said sample chamber including apassageway between said chamber and the exterior of said housing, aYclosure in said passageway, an elongated rod, and spring meansconnected to said rod for driving said rod against said closure to anoperative position of said rod to open said closure and permit uid entryinto said charnber;

a sear positioned in said housing to hold said rod away from saidoperative position thereof;

spring means supported in said housing and connected to said sear forurging said sear away from the rodholding position thereof;

rotatable cam means;

driving means connecting said cam means to said timing motor including alost motion coupling adapted to permit free rotation of said cam meansthrough a limited are of movement;

said cam means having a cam surface withra substantially constant radiusportion and a valley portion; and

a cam follower on said Sear in folle-wing relationship with said camsurface to hold said sear in the rodholding position thereof whilefollowing the constant radius portion of said cam, and to release saidscar from the rod-holding position thereof -while following the valleyportion of said cam assemblyY whereby said Sear releases said rod toopen said sample chamber.`

3.' A'deep `well sampler comprising:

an elongated housing;

a sample chamber in said housing;

a passageway into said chamber from the exterior of the housing;

a frangible seal in the passageway;

a spear-like member in said housing positioned in line with said seal tobe driven at said seal for rupturing said seal;

spring means supported in said housing and Vconnected to said spear-likemember to drive said spear-like member at said seal;

a sear pivotally supported in said housing latching said spear-likemember to hold said Ispear-like member away from said seal against theforce of said spring;

a timing motor in said housing;

a cam shaft in said housing, `connected to said timing motor and drivenby said timing motor;

a 'cam on said shaft;

a lost motion coupling connecting said cam to -said` `shaft so as topermit said cam to freely rotate through a predetermined are of movementbetween 45 and 90 on the shaft and adapted to fbe rota- 'tively drivenby said shaft, said cam having a cam surface with a first substantiallyconstant radius portion and a cam valley;

a cam follower on Said 'sear lbiased against the cam surface of sai-dcam so that said cam surface holds said sear in latching relationshipwith said spear-like member while following the constant radius portionthereof, and to release said spear-like member when said cam followerrolls into said valley; and

means in said housing connected to said Sear to urge said cam followeragainst the cam surface.

References Cited in the iile of this patent UNITED STATES PATENTS2,577,210 Ruska Dec. 4, 1951 2,728,397 Ruska Dec. 27, 1955 2,927,754Buck Mar. 8, 1960

